[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Proton pump inhibitors (PPIs)](https://durgical.com/en/pharmacology/classes/proton-pump-inhibitors/) › Esomeprazole

[Pharmacology](https://durgical.com/en/pharmacology/) · [Proton pump inhibitors (PPIs)](https://durgical.com/en/pharmacology/classes/proton-pump-inhibitors/)

# Esomeprazole

The S-isomer of omeprazole, a proton pump inhibitor given by mouth or IV. Like omeprazole, it inhibits CYP2C19 and is avoided with clopidogrel.

Updated 2026-11-01

- Class: [Proton pump inhibitors (PPIs)](https://durgical.com/en/pharmacology/classes/proton-pump-inhibitors/)
- Transporter: Gastric H⁺/K⁺-ATPase (proton pump), α subunit
- ATC code: A02BC05

⇄**Gastric H⁺/K⁺-ATPase (proton pump), α subunit**Esomeprazole

ⓘ The crystal is the pig gastric pump bound to vonoprazan, a reversible acid blocker; the figure highlights Cys813, the cysteine to which activated esomeprazole bonds covalently.

**Target in 3D:** Gastric H⁺/K⁺-ATPase (proton pump), α subunit. PDB structure 5YLU (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/5YLU) · Drag to rotate · pinch to zoom

## Mechanism of action

Esomeprazole is the S-enantiomer of omeprazole. Like the other PPIs it is a prodrug that collects in the acidic canaliculus of the parietal cell, is converted by acid into a reactive sulfenamide and bonds covalently to cysteines of the H⁺/K⁺-ATPase, blocking the final step of acid secretion until new pumps are made. It also inhibits CYP2C19 in a time-dependent way, so its own levels rise with repeated doses.

- The S-isomer of omeprazole collects in the parietal cell canaliculus
- Acid activates it into a reactive sulfenamide
- A covalent bond to Cys813 locks the H⁺/K⁺ pump
- Acid falls until the cell makes new pumps

## Pharmacokinetics

**Absorption**
Delayed-release forms; food lowers absorption markedly, so it is taken at least an hour before a meal. IV forms exist.

**Metabolism**
Liver, by CYP2C19 and CYP3A4; it inhibits CYP2C19 itself, so exposure rises more than proportionally with repeated doses.

**Elimination**
About 80% leaves as inactive metabolites in the urine and the rest in the faeces.

**Half-life**
Short in plasma, but the effect on the pump lasts much longer.

## Indications

- Healing and maintenance of erosive oesophagitis, and symptomatic reflux. [Gastro-oesophageal reflux disease (GERD) →](https://durgical.com/en/conditions/gastro-oesophageal-reflux-disease/)
- H. pylori eradication with amoxicillin and clarithromycin to reduce duodenal ulcer recurrence. [Helicobacter pylori gastritis →](https://durgical.com/en/conditions/helicobacter-pylori-gastritis/)
- Lowering the risk of gastric ulcer in patients on continuous NSAIDs. [Peptic ulcer disease →](https://durgical.com/en/conditions/peptic-ulcer-disease/)
- Zollinger–Ellison syndrome and other hypersecretory states. [Zollinger-Ellison syndrome (gastrinoma) →](https://durgical.com/en/conditions/zollinger-ellison-syndrome/)

## Adverse effects

### Common

- Headache
- Diarrhoea, nausea, abdominal pain, flatulence and constipation
- Dry mouth

### Serious (rare, important)

- Acute tubulointerstitial nephritis
- Clostridioides difficile diarrhoea
- Fractures with long, high-dose use
- Low magnesium and vitamin B12 deficiency with prolonged use
- Cutaneous or systemic lupus erythematosus; fundic gland polyps

## Contraindications

- Hypersensitivity to esomeprazole or other substituted benzimidazoles
- Use with rilpivirine-containing products

## Key interactions

**Clopidogrel**
Esomeprazole inhibits CYP2C19, reduces clopidogrel's active metabolite and weakens platelet inhibition; the combination is avoided.

**Citalopram**
Higher citalopram exposure and more risk of QT prolongation.

**Cilostazol and digoxin**
Higher exposure to these drugs.

**Atazanavir and nelfinavir**
Lower antiretroviral levels, loss of effect and resistance; nelfinavir is avoided with it.

**Rifampicin and St John's wort**
They induce CYP2C19 and CYP3A4 and markedly lower esomeprazole levels.

## What is monitored

- Magnesium before and during long treatment, especially with digoxin or diuretics
- Kidney function if fever, rash or rising creatinine appear
- Periodic review of whether it is still needed

## Administration and safety

- Taken at least an hour before a meal, because food lowers absorption
- Capsules are swallowed whole; delayed-release forms are not crushed or chewed
- Check for clopidogrel in the medication list; another PPI or an H2 blocker may be preferred
- IV forms are used when oral intake is not possible

## Nursing care

- Schedule the dose before breakfast
- Review the medication list for clopidogrel, citalopram and antiretrovirals
- Check magnesium in long-term use, mainly with diuretics or digoxin
- Teach the patient to report watery diarrhoea, fever or rash

## Pregnancy and breastfeeding

Epidemiological data on esomeprazole and omeprazole have not shown more major malformations; it is used when needed.

## Memory aid

«ESomeprazole = the S-ide of omeprazole»: same pump lock, same CYP2C19 fight with clopidogrel, taken an hour before breakfast.

## Test yourself

Think of the answer, then tap the question to see it.

## How is esomeprazole related to omeprazole?

It is omeprazole's S-enantiomer (S-isomer).

## Why is esomeprazole avoided in a patient on clopidogrel?

It inhibits CYP2C19, which converts clopidogrel into its active metabolite, so platelet inhibition is weaker.

## Why is esomeprazole taken at least an hour before a meal?

Food markedly lowers its absorption.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/esomeprazole/)

## Related drugs

- [Omeprazole](https://durgical.com/en/pharmacology/omeprazole/)
- [Pantoprazole](https://durgical.com/en/pharmacology/pantoprazole/)
- [Lansoprazole](https://durgical.com/en/pharmacology/lansoprazole/)

## Related conditions

- [Gastro-oesophageal reflux disease (GERD)](https://durgical.com/en/conditions/gastro-oesophageal-reflux-disease/)
- [Helicobacter pylori gastritis](https://durgical.com/en/conditions/helicobacter-pylori-gastritis/)
- [Peptic ulcer disease](https://durgical.com/en/conditions/peptic-ulcer-disease/)
- [Zollinger-Ellison syndrome (gastrinoma)](https://durgical.com/en/conditions/zollinger-ellison-syndrome/)

[← Back to the class: Proton pump inhibitors (PPIs)](https://durgical.com/en/pharmacology/classes/proton-pump-inhibitors/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - ESOMEPRAZOLE MAGNESIUM capsule, delayed release pellets](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e04e7c84-59c8-4a1d-8dfc-d72588b97b59) (DailyMed (U.S. National Library of Medicine), 2026); [Esomeprazole: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a699054.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [Medications for the Treatment of Gastric Acidity - Gastroenterology - MSD Manual Professional Edition](https://www.msdmanuals.com/professional/gastrointestinal-disorders/gastritis-and-peptic-ulcer-disease/drug-treatment-of-gastric-acidity) (MSD Manual Professional Edition, 2025); [RCSB PDB - 5YLU: Crystal structure of the gastric proton pump complexed with vonoprazan](https://www.rcsb.org/structure/5YLU) (RCSB Protein Data Bank, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/pharmacology/esomeprazole/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/esomeprazole/